Implant delivery system

ABSTRACT

An implant delivery system comprises an elongate tubular member having a lumen, a tubular implant coaxially disposed within the lumen of the elongate tubular member, and a delivery assembly having a distal portion coaxially disposed within tubular implant. The delivery assembly comprises a delivery wire, an engaging bumper fixedly coupled to the delivery wire, a stopper bumper fixedly coupled to the delivery wire, and a floating element slidably coupled around the delivery wire and disposed between the bumpers, thereby limiting linear translation of the floating element therebetween. The floating element has an engaging portion configured to engage the engaging bumper when the delivery wire is axially translated relative to the elongate member in a first direction. The floating element is configured to radially expand outward to frictionally engage the implant when the engaging portion of the floating element engages the engaging bumper.

FIELD

The present disclosure relates generally to medical devices andintravascular medical procedures and, more particularly, to devices andmethods for delivering an implant to a target site in a blood or otherbody vessel.

BACKGROUND

The use of intravascular medical devices has become an effective methodfor treating many types of vascular disease. In general, a suitableintravascular device is inserted into the vascular system of the patientand navigated through the vasculature to a desired target site. Usingthis method, virtually any target site in the patient's vascular systemmay be accessed, including the coronary, cerebral, and peripheralvasculature.

Medical implants, such as stents, stent grafts, flow-diverters, and venacava filters, are often utilized in combination with a delivery devicefor placement at a desired location within the body. A medical implant,such as a stent, may be loaded into a stent delivery device and thenintroduced into the lumen of a body vessel in a configuration having areduced diameter. Once delivered to a target location within the body,the stent may then be expanded to an enlarged configuration within thevessel to support and reinforce the vessel wall while maintaining thevessel in an open, unobstructed condition. The stent may be configuredto be self-expanding, expanded by a stored potential radial force suchas a balloon, or a combination of self-expanding and balloon expanded.

There is an ongoing need to provide alternative stent delivery devicesthat delivery medical implants into the vasculature of a patient.

SUMMARY

In accordance with a first embodiment of the disclosed inventions, animplant delivery system comprises an elongate tubular member having alumen, a tubular implant coaxially disposed within the lumen of theelongate tubular member, and a delivery assembly having a distal portioncoaxially disposed within tubular implant.

In accordance with one aspect of the disclosed inventions, the deliveryassembly comprises a delivery wire, an engaging bumper fixedly coupledto the delivery wire, a stopper bumper fixedly coupled to the deliverywire, and a floating element slidably coupled around the delivery wireand disposed between the bumpers, thereby limiting linear translation ofthe floating element therebetween. The floating element has an engagingportion configured to engage the engaging bumper when the delivery wireis axially translated relative to the elongate member in a firstdirection, wherein the floating element is configured to radially expand(e.g., by flaring outward) to frictionally engage the implant when theengaging portion of the floating element engages the engaging bumper.

In one embodiment, the floating element comprises an annular portionslidably disposed around the delivery wire. The annular portion isconfigured to contact the stopper bumper when the delivery wire isaxially translated relative to the elongate member in a second directionopposite to the first direction. The floating element is configured tomaintain a radially unexpanded configuration in which the floatingelement does not frictionally engage the implant when the annularportion of the floating element contacts the stopper bumper. In variousembodiments, the engaging portion of the floating element has an innersurface, and the engaging bumper has an outer surface that engages theinner surface of the floating element when the delivery wire is axiallytranslated relative to the elongate member in the first direction. Forexample, the outer surface of the engaging bumper may taper inwardstowards the engaging portion of the floating element.

In one embodiment, the annular portion of the floating element has anabutting surface and the stopper bumper has a corresponding abuttingsurface that abuts the abutting surface of the floating element when thedelivery wire is axially translated relative to the elongate member inthe second direction. In this case, the abutting surface of the stopperbumper may be substantially perpendicular to the second direction.

The engaging portion of the floating element may have one of afunnel-like, flower-like, and skirt-like configuration. For example, theengaging portion of the floating element may have a funnel-likeconfiguration including an elastically compressible bent sectiondisposed between two straight sections. The engaging portion of thefloating element may have a flower-like configuration including aplurality of petal-like elements. The engaging portion of the floatingelement may have a flower-like configuration including a plurality offlaps.

In accordance with another embodiment of the disclosed inventions, adelivery assembly comprises a delivery wire, a first set of bumpersincluding a first engaging bumper and a first stopper bumper fixedlycoupled to the delivery wire, a second set of bumpers including a secondengaging bumper and a second stopper bumper fixedly coupled to thedelivery wire, and a set of floating elements including a first floatingelement and a second floating element slidably coupled around thedelivery wire.

The first floating element is disposed between the first engaging bumperand the first stopper bumper, thereby limiting linear translation of thefirst floating element therebetween. The first floating element has anengaging portion configured to engage the first engaging bumper when thedelivery wire is axially translated in a first direction. The firstfloating element is configured to radially expand (e.g., by flaringoutward) to frictionally engage the implant when the engaging portion ofthe first floating element engages the first engaging bumper.

The second floating element is disposed between the second engagingbumper and the second stopper bumper, thereby limiting lineartranslation of the second floating element therebetween. The secondfloating element has an engaging portion configured to engage the secondengaging bumper when the delivery wire is axially translated relative tothe elongate member in a second direction opposite the first direction.The second floating element is configured to radially expand (e.g., byflaring outward) to frictionally engage the implant when the engagingportion of the second floating element engages the second engagingbumper.

In one embodiment, the first floating element comprises an annularportion slidably disposed around the delivery wire. The annular portionis configured to contact the first stopper bumper when the delivery wireis axially translated relative to the elongate member in the seconddirection. The engaging portion of each of the first and second floatingelements may have one of a funnel-like, flower-like, and skirt-likeconfiguration. The first floating element is configured to maintain anon-radially expanded configuration in which the first floating elementdoes not frictionally engage the implant when the annular portion of thefirst floating element contacts the first stopper bumper. The secondfloating element comprises an annular portion slidably disposed aroundthe delivery wire. The annular portion is configured to contact thesecond stopper bumper when the delivery wire is axially translatedrelative to the elongate member in the first direction. The secondfloating element is configured to maintain a non-radially expandedconfiguration in which the second floating element does not frictionallyengage the implant when the annular portion of the second floatingelement contacts the second stopper bumper.

In one such embodiment, the engaging portion of the first floatingelement has an inner surface and the first engaging bumper has acorresponding outer surface that tapers towards the engaging portion ofthe first floating element and engages the inner surface of the firstfloating element when the delivery wire is axially translated relativeto the elongate member in the first direction, and the engaging portionof the second floating element has an inner surface and the secondengaging bumper has a corresponding outer surface that tapers towardsthe engaging portion of the second floating element and that engages theinner surface of the second floating element when the delivery wire isaxially translated relative to the elongate member in the seconddirection.

In one such embodiment, the annular portion of the first floatingelement has an abutting surface, and the first stopper bumper has anabutting surface perpendicular to the second direction that abuts theabutting surface of the first floating element when the delivery wire isaxially translated relative to the elongate member in the seconddirection, and the annular portion of the second floating element has anabutting surface, and the second stopper bumper has an abutting surfaceperpendicular to the first direction that abuts the abutting surface ofthe second floating element when the delivery wire is axially translatedrelative to the elongate member in the first direction.

In accordance with a yet another embodiment, a method of operating theimplant delivery system is provided, wherein the implant delivery systemcomprises an elongate tubular member having a lumen, a tubular implantcoaxially disposed within the lumen of the elongate tubular member, anda delivery assembly having a distal portion coaxially disposed withintubular implant, and the delivery assembly comprises a delivery wire, afirst engaging bumper fixedly coupled to the delivery wire, a firststopper bumper fixedly coupled to the delivery wire, and a firstfloating element slidably coupled around the delivery wire and disposedbetween the first bumpers, the method comprising axially translating thedelivery wire relative to the elongate member in a first direction,while limiting linear translation of the first floating element betweenthe first engaging bumper and the first stopper bumper, engaging thefirst engaging bumper with an engaging portion of the first floatingelement, such that the first floating element radially expands outwardto frictionally engage the implant, and further axially translating thedelivery wire relative to the elongate member in the first direction,thereby advancing the implant within the lumen of the elongate tubularmember. The delivery wire may be further axially translated relative tothe elongate member until the implant at least partially deploys out ofthe lumen of the elongate tubular member.

The deliver assembly may further comprise a second engaging bumperfixedly coupled to the delivery wire, a second stopper bumper fixedlycoupled to the delivery wire, and a second floating element slidablycoupled around the delivery wire and disposed between the secondbumpers.

In this case, the method may further comprise axially translating thedelivery wire relative to the elongate member in a second directionopposite to the first direction, while limiting linear translation ofthe second floating element between the second engaging bumper and thesecond stopper bumper, disengaging the first engaging bumper from theengaging portion of the first floating element, such that the firstfloating element radially contracts inwards to release the implant,engaging the second engaging bumper with an engaging portion of thesecond floating element, such that the second floating element radiallyexpands outward to frictionally engage the implant, and continuing toaxially translate the delivery wire relative to the elongate member inthe second direction, thereby resheathing the implant within the lumenof the elongate tubular member.

Other and further aspects and features of embodiments of the disclosedinventions will become apparent from the ensuing detailed description inview of the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate the design and utility of preferred embodimentsof the disclosed inventions, in which similar elements are referred toby common reference numerals. It should be noted that the figures arenot drawn to scale and that elements of similar structures or functionsare represented by like reference numerals throughout the figures. Itshould also be noted that the figures are only intended to facilitatethe description of the embodiments, without intention to be anexhaustive description or as a limitation on the scope of the disclosedinventions, which is defined only by the appended claims and theirequivalents. In addition, the illustrated embodiments need not have allthe aspects or advantages shown, and an aspect or an advantage describedin conjunction with a particular embodiment is not necessarily limitedto that embodiment and can be practiced in other embodiments, even ifnot so illustrated. In order to better appreciate how the above-recitedand other advantages and objects are obtained, a more particulardescription of the disclosed inventions briefly described above will berendered by reference to specific embodiments thereof, which areillustrated in the accompanying drawings, in which:

FIG. 1 is a side view of an implant delivery system constructedaccording to one embodiment of the disclosed inventions, with a distalregion of the system shown in an inset;

FIG. 2 is a cross-sectional view of the distal portion of the implantdelivery system constructed according to one embodiment of the disclosedinventions;

FIG. 3 is a cross-sectional view of the implant delivery system of FIG.2, showing advancement of the delivery assembly and engaging the implantfor delivery;

FIG. 4 is a cross-sectional view of the implant delivery system of FIG.2, showing withdrawal of the delivery assembly and engaging the implantfor re-sheathing;

FIGS. 5A-5D are cross-sectional views an alternative embodiment of theimplant delivery system of FIG. 2, particularly showing the process ofengaging the implant;

FIG. 6 is a perspective view of one embodiment of a floating elementthat can be used in the implant delivery system of FIG. 1 or FIG. 5;

FIG. 7 is a perspective view of another embodiment of a floating elementthat can be used in the implant delivery system of FIG. 1 or FIG. 5;

FIGS. 8A-8B are perspective views of embodiments of a floating elementthat can be used in the implant delivery system of FIG. 1 or FIG. 5; and

FIG. 9 is a flow diagram illustrating one method of operating theimplant delivery system of FIG. 2.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Referring first to FIG. 1, one embodiment of an implant delivery system10 constructed in accordance with one embodiment of the disclosedinventions will be described. The implant delivery system 10 generallycomprises an elongate tubular member 12, a tubular implant 20 (not shownin FIG. 1), and a delivery assembly 30.

The elongate member 12 has a tubular configuration, and can, e.g., takethe form of a sheath, catheter, micro-catheter or the like. The elongatemember 12 has a proximal portion 13, a distal portion 16, and a lumen 17extending through the elongate member 12 between the proximal portion 13and the distal portion 16. The proximal section 13 of the elongatemember 12 remains outside of the patient and accessible to the operatorwhen the implant delivery system 10 is in use, while the distal portion16 of the elongate member 12 is sized and dimensioned to reach remotelocations of a vasculature and is configured to deliver the implant 20to a target location in a patient's body, such as an occlusion in ablood vessel, in a blood vessel adjacent to an aneurysm neck, abifurcated blood vessel, or the like. The implant delivery system 10 hasat least one fluid port 15 in fluid communication with the elongatemember 12, which is used to introduce fluids into the elongate member12. The implant 20 and delivery assembly 30 are disposed in the lumen 17of the elongate member 12 of the implant delivery system 10, as betterappreciated in FIG. 2.

The implant 20, such a stent or a flow diverter, includes a tubularresilient member having a proximal portion 22, a distal portion 24, anddefining an inner lumen 26 extending therebetween (FIG. 2). The implant20 has a delivery configuration when disposed within the lumen 17 of theelongate member 12 and/or is radially constrained by the elongate member12. The implant 20 is biased to expand radially outwards into a deployedconfiguration in which the implant 20 is expanded when deployed out ofthe elongate member 12. The implant 20 may be constructed from a varietyof materials such as stainless steel, elgiloy, nickel, titanium,nitinol, shape memory polymers, or combinations thereof. The implant 20may also be formed in a variety of manners as well. For example, theimplant 20 may be formed by etching or cutting a pattern from a tube orsheet of stent material; a sheet of stent material may be cut or etchedaccording to a desired stent pattern whereupon the sheet may be rolledor otherwise formed into the desired substantially tubular, bifurcatedor other shape. For the implant 20, one or more wires or ribbons ofstent material may be woven, braided or otherwise formed into a desiredshape and pattern. The implant 20 may include further components thatare welded, bonded or otherwise engaged to one another. The implant 20may include a non-porous, non-permeable biocompatible material, cover orthe like, when the implant 20 is used as a blood flow diverter.

The implant delivery system 10 may be used in an “over-the-wire”configuration, wherein the elongate member 12 is introduced into thepatient over a guidewire which has been previously introduced, and theelongate member 12 extends over the entire length of the guidewire (notshown). Alternatively, the implant delivery system 10 may be used in a“rapid-exchange” configuration, where a guidewire extends through only adistal portion of the implant delivery system 10 from a guidewire port(not shown). In other alternative embodiments, the implant deliverysystem 10 may be introduced into the patient after a guidewire had beenwithdrawn leaving a sheath or access catheter distal portion at thetarget site for the assembly 10 to navigate through the vasculature ofthe patient within the sheath or access catheter.

The implant delivery system 10 may include one or more, or a pluralityof regions along its length having different configurations and/orcharacteristics. For example, the distal portion 16 of the elongatemember 12 may have an outer diameter less than the outer diameter of theproximal portion 13 to reduce the profile of the distal portion 16 andfacilitate navigation in tortuous vasculature (FIG. 1). Furthermore, thedistal portion 16 may be more flexible than the proximal portion 13.Generally, the proximal portion 13 may be formed from material that isstiffer than the distal portion 16 of the elongate member 12, so thatthe proximal portion 13 has sufficient pushability to advance throughthe patient's vascular system, while the distal portion 16 may be formedof a more flexible material so that the distal portion 16 may remainflexible and track more easily over a guidewire to access remotelocations in tortuous regions of the vasculature. The elongate member 12may be composed of suitable polymeric materials, metals and/or alloys,such as polyethylene, stainless steel or other suitable biocompatiblematerials or combinations thereof. In some instances, the proximalportion 13 may include a reinforcement layer, such a braided layer orcoiled layer to enhance the pushability of the elongate member 12. Theelongate member 12 may include a transition region between the proximalportion 13 and the distal portion 16.

Referring further to FIG. 2, the implant 20 is coaxially disposed withinthe distal portion 16 of elongate member 12, and the delivery assembly30 is coaxially disposed and axially movable relative to the elongatemember 12 and the implant 20. The delivery assembly 30 is configured toengage the implant 20 when the system 30 is axially translated relativeto the elongate member 12 for delivery of the implant 20 into a targetsite of a patient. The interface between the delivery assembly 30 andthe implant 20 will be described in further detail below.

The delivery assembly 30 comprises a delivery wire 31 having a proximalregion 32 and a distal region 33 (FIG. 1). The delivery wire 31 may bemade of a conventional guidewire, torqueable cable tube, a hypotube orthe like. In either case, there are numerous materials that can be usedfor the delivery wire 31 to achieve the desired properties that arecommonly associated with medical devices. Some examples can includemetals, metal alloys, polymers, metal-polymer composites, and the like,or any other suitable material. For example, the delivery wire 31 mayinclude nickel-titanium alloy, stainless steel, a composite ofnickel-titanium alloy and stainless steel. In some cases, the deliverywire 31 can be made of the same material along its length, or in someembodiments, can include portions or sections made of differentmaterials. In some embodiments, the material used to construct thedelivery wire 31 is chosen to impart varying flexibility and stiffnesscharacteristics to different portions of the delivery wire 31. Forexample, the proximal region and the distal region 33 of the deliverywire 31 may be formed of different materials, such as materials havingdifferent moduli of elasticity, resulting in a difference inflexibility. For example, the proximal region 32 can be formed ofstainless steel, and the distal region 33 can be formed of anickel-titanium alloy. However, any suitable material or combination ofmaterial may be used for the delivery wire 31, as desired.

The delivery wire 31 may further include a distal shapeable orpre-shaped atraumatic end 34 (FIG. 2), which may aid the advancement ofthe delivery wire 31. In some embodiments, the distal end 34 may includea coil placed over a portion of a distal end of the delivery wire 31(not shown) or, alternatively, may include a material melted down andplaced over a portion of the distal end 34 of the delivery wire 31. Insome embodiments, the distal end 34 may include a radiopaque material toaid in visualization. Additionally, the distal end 34 of the deliverywire 31 may be floppy and steerable using pull wires (not shown) tofacilitate tracking of the delivery assembly 30 through a vessel toreach a target site. Although not illustrated, it is contemplated thatthe distal end 34 of the delivery wire 31 may include one or moretapered sections, as desired.

The delivery wire 31 may optionally include one or more bands (notshown) in the distal region 33 of the delivery wire 31. The bands may beformed integrally into the delivery wire 31, or they may be separatelyformed from the delivery wire 31 and attached thereto. In someembodiments, the bands may be disposed on the delivery wire 31. Thebands may have a diameter greater than the diameter of the surroundingthe delivery wire 31. Bands may be formed of any suitable material, suchas metals, metal alloys, polymers, metal-polymer composites, and thelike, or any other suitable material, as well as any radiopaquematerial, as desired. Alternatively, it is contemplated that thedelivery wire 31 may include one or more recesses instead of providingbands, if desired.

Significantly, the delivery assembly 30 comprises at least one set ofbumpers 40 fixedly coupled to the delivery wire 31, and a floatingelement 50 slidably coupled to the delivery wire 31. In the embodimentof FIG. 2, two sets of bumpers 40 (a first set of distal bumpers 40′ anda second set of proximal bumpers 40″) are disposed at the distal portion32 of the delivery wire 31, with each set having a respective floatingelement 50′/50″ therebetween. In particular, the distal bumpers 40′include a distal engaging bumper 42′ and a distal stopper bumper 44′,with a distal floating element 50′ therebetween, and the proximalbumpers 40″ include a proximal engaging bumper 42″ and a proximalstopper bumper 44″, with a proximal floating element 50″ therebetween.The engaging bumpers 42/42′/42″ and the stopper bumpers 44/44′/44″ areconfigured to limit translation of the respective floating elements50/50′/50″ therebetween. Additionally, the engaging bumpers 42/42″/42″are configured to interface with the respective floating elements50/50′/50″ to engage (i.e., frictionally engage) the implant 20 fordelivery to a target site (FIGS. 3, 5A-D) and/or re-sheathing theimplant 20 into the elongate member 12 (FIG. 4).

Each floating element 50/50′/50″ has an annular portion 51/51′/51″, suchas a collar, ring or the like, and engaging portion 52/52′/52″ having aninner surface 53/53′/53″ configured to interface with an outer surface43/43′/43″ of the engaging bumper 42/42′/42″ when the delivery assembly30 is actuated, which is described in further detail below.

Between the distal set of bumpers 40′, the engaging portion 52′ of thedistal floating element 50′ is proximately disposed to the annularportion 51′ of the distal floating element 50′, such that the interfacebetween the distal engaging bumper 42′ and engaging portion 52′ of thedistal floating element 50′ is configured to engage the implant 20 whenthe delivery wire 31 is advanced or translated in the distal directionfor delivery of the implant 20 into the target site of the patient (FIG.3).

In contrast, between the proximal set of bumpers 40″, the engagingportion 52″ of the proximal floating element 50″ is distally disposed tothe annular portion 51 of the proximal floating element 50″, such thatthe interface between the proximal engaging bumper 42″ and engagingportion 52″ of the proximal floating element 50″ is configured to engagethe implant 20 when the delivery wire 31 is withdrawn or translated inthe proximal direction for re-sheathing of the implant 20 into theelongate member 12 (FIG. 4).

As shown in FIG. 3, the delivery assembly 30 is actuated by advancing(i.e., distally translating, axially moving) the delivery wire 31relative to the elongate member 12. When the delivery wire 31 isadvanced relative to the elongate member 12, the distal engaging bumper42′ interfaces with the engaging portion 52′ of the distal floatingelement 50′, wherein the outer surface 43′ of the engaging bumper 42′contacts the inner surface 53′ of the engaging portion 52′, so that theengaging portion 52′ of the distal floating element 50′ is disposedbetween the distal engaging bumper 42′ and the implant 20. The interfacebetween the distal engaging bumper 42′ and the engaging portion 52′ ofthe distal floating element 50′ exerts a radially outward force on aninterior surface 25 of the implant 20. This radially outward force issufficient to contact and frictionally engage the implant 20 so as toadvance and deliver the implant 20 to a target site when the deliverywire 31 advances relative to the elongate member 12. Furthermore, whenthe delivery wire 31 is advanced relative to the elongate member 12, theproximal stopper bumper 44″ contacts the annular portion 51″ of theproximal floating element 50″, advancing and distally pushing theproximal floating element 50″ along with the advancement of the deliverywire 31. As shown in FIG. 3, the proximal floating element 50″ does notfrictionally engage the implant 20 during advancement of the deliverywire 31.

As shown in FIG. 4, the delivery assembly 30 is actuated by withdrawing(i.e., proximately translating, axially moving) the delivery wire 31relative to the elongate member 12. When the delivery wire 31 iswithdrawn relative to the elongate member 12, the proximal engagingbumper 42″ interfaces with the engaging portion 52″ of the proximalfloating element 50″, wherein the outer surface 43 of the engagingbumper 42″ contacts the inner surface 53″ of the engaging portion 52″,so that the engaging portion 52″ of the proximal floating element 50″ isdisposed between the proximal engaging bumper 42″ and the implant 20.The interface between the proximal engaging bumper 42″ and the engagingportion 52 of the proximal floating element 50″ exerts a radiallyoutward force on the interior surface 25 of the implant 20. Thisradially outward force is sufficient to frictionally engage the implant20 so as to withdraw and re-sheath the implant 20 when the delivery wire31 is withdrawn relative to the elongate member 12. Furthermore, whenthe delivery wire 31 is withdrawn relative to the elongate member 12,the distal stopper bumper 44′ contacts the annular portion 51′ of thedistal floating element 50′, withdrawing and proximally pushing thedistal floating element 50′ along with the withdrawal of the deliverywire 31. As shown in FIG. 4, the distal floating element 50′ does notfrictionally engage the implant 20 during withdrawal of the deliverywire 31.

Thus, as can be appreciated, the delivery assembly 30 of the implantdelivery system 10 comprises a bi-directional actuation. Particularly,as shown in FIG. 3, when the delivery wire 31 is axially translatedrelative to the elongate member 12 in a first direction (i.e., advancedin a distal direction), the implant 20 is engaged by the interfacebetween the distal engaging bumper 42′ and the engaging portion 52′ ofthe distal floating element 50′, while the proximal floating element 50″does not engage the implant 20. Conversely, as shown in FIG. 4, when thedelivery wire 31 is axially translated relative to the elongate member12 in a second direction, opposite to the first direction (i.e.,withdrawn in a proximal direction), the implant 20 is engaged by theinterface between the proximal engaging bumper 42″ and the engagingportion 52″ of the proximal floating element 50″, while the distalfloating element 50′ does not engage the implant 20. The bi-directionaldelivery assembly 30 provides the operator of the implant deliverysystem 10 with the advantage of being able to both deliver or re-sheaththe implant 20 by either advancing or withdrawing the delivery wire 31relative to the elongate member 12.

While the embodiment depicted in FIGS. 2-4 comprises a delivery assembly30 having two sets of bumpers 40′ and 40″, each having a respectivefloating member 50′/50″, an alternative embodiment of the deliveryassembly 30 may have more than two sets of bumpers 40 and floatingmembers 50. Still another embodiment of the delivery assembly 30 maycomprise only one set of bumpers 40 with only one floating member 50.

For example, as shown in FIGS. 5A-D, the delivery assembly 30 comprisesone set of bumpers 40 and one floating element 50 for delivery of theimplant 20 into the target site. The delivery assembly 30 is actuated byadvancing (i.e., distally translating, axially moving) the delivery wire31 relative to the elongate member 12. When the delivery wire 31 isadvanced relative to the elongate member 12, the engaging bumper 42approaches the floating element 50 (FIGS. 5A-B), and as the deliverywire 31 further advances, the outer surface 43 of the engaging bumper 42interfaces with (i.e., contacts) the inner surface 53 the engagingportion 52 of the floating element 50 (FIG. 5C), so that the engagingportion 52 of the floating element 50 is disposed between the engagingbumper 42 and the implant 20, frictionally engaging the implant 20 (FIG.5D). As best seen in FIG. 5D, the interface between the engaging bumper42 and the engaging portion 52 of the floating element 50 exerts aradially outward force (shown by arrows in FIG. 5D) on an interiorsurface 25 of the implant 20. This radially outward force is sufficientto frictionally engage implant 20 so as to advance the implant withinthe elongate member 12, and deliver the implant 20 to a target site whenthe delivery wire 31 advances relative to the elongate member 12.

In the embodiments of FIGS. 2-5D, each floating element 50/50′/50″ isconfigured to radially expand outward (e.g., by flaring outward) tofrictionally engage the implant 20 when the engaging portion 52/52′/52″of the floating element 50/50′/50″ engages the respective engagingbumper 42/42′/42″. In some embodiments, the engaging portion 52/52′/52″of the floating elements 50/50′/50″ is dimensioned and sized topartially enter or occupy openings/cells in the implant 20 (FIG. 5D),thereby allowing further engagement and/or frictional forces between thedelivery assembly 30 and the implant 20. This design assists the axialdisplacement of the implant 20 relative to the elongate element 12,further facilitating delivery or re-sheathing of the implant 20.

In these embodiments and as best seen in FIG. 5C, the outer surface 43of the engaging bumper 42 engages the inner surface 53 of the floatingelement 50 to radially expand the floating element 50 outwardly andfrictionally contact and/or engage the implant 20 for translationrelative to the elongate element 12. To facilitate engagement betweenthe engaging portion 52 of the floating element 50 and the respectiveengaging bumper 42, and the consequential outward radial expansion ofthe floating element 52, in the illustrated embodiments, the outersurface 43 of the engaging bumper 42 tapers inwards towards the engagingportion 52 of the respective floating element 52. While the engagingbumpers 42/42′/42″ depicted in FIGS. 2-5D comprise a disk-shape having atapered annular portion, the engaging bumpers 42/42′/42″ may include avariety of configurations having any cross-section, such as irregularshapes, as long as at least one cross-sectional dimension is suitable tointerface with the inner surface 53/53′/53″ of the engaging portion52/52′/52″ of the floating element 50/50′/50″ and frictionally engagethe implant 20, as previously described.

In the embodiments of FIGS. 2-5D, each floating element 50/50′/50″ isconfigured to not radially expand outwardly (e.g., by not flaringoutwardly), such that there is no frictional engagement with the implant20 when the floating element 50/50′/50″ engages the respective stopperbumper 44/44′/44″. In these embodiments, the annular portion 51/51′/51″of each floating element 50/50′/50″ has an abutting surface 58/58′/58″,and the respective stopper bumper 44/44′/44″ has an abutting surface48/48′/48″ that abuts the abutting surface 58/58′/58″ of the floatingelement 50/50′/50″ to axially displace the floating element 50/50′/50″relative to the implant 20. To facilitate engagement between thefloating element 50/50′/50″ and the respective stopper bumper44/44′/44″, and the consequential axial displacement of the floatingelement 50/50′/50″ relative to the implant 20, the abutting surface58/58′/58″ of the annular portion 51/51′/51″ of each floating element50/50′/50″ and the abutting surface 48/48′/48″ of the stopper bumper44/44′/44″ are both perpendicular to the axial movement of the floatingelement 50/50′/50″. While the stopper bumpers 44/44′/44″ depicted inFIGS. 2-5D comprise a disk-shape configuration, and the stopper bumpers44/44′/44″ may comprise a variety of configuration, including irregularshapes, as long as at the stopper bumpers 44/44′/44″ axially translatesthe floating element 50/50′/50″ over the delivery wire 31 relative tothe implant 20, as previously described.

As depicted in FIGS. 2-5D, the engaging bumpers 42/42′/42″ and thestopper bumpers 44/44′/44″ have respective cross-sectional dimensionsthat are smaller than the inner diameter of the implant 20 in thedelivery configuration, when the implant 20 is disposed within the lumen17 of the elongate member 12. In the embodiments of FIGS. 2-4, theengaging bumpers 42/42′/42″ have a cross-sectional dimension larger thanthe stopper bumpers 44/44′/44″. In the embodiments of FIGS. 5A-D, theengaging bumper 42/42′/42″ has a cross-sectional dimension substantiallysimilar to the stopper bumper 44/44′/44″. It should be appreciated thatvariations of the relative dimensions of the engaging bumpers 42/42′/42″and the stopper bumpers 44/44′/44″ may be suitable in some embodiments.

In the embodiments depicted in FIGS. 2-8B, the engaging portion52/52′/52″ extending from the annular portion 51/51′/51″ of the floatingelement 50/50′/50″ is composed of suitable biocompatible materialconfigured to be elastically compressible, for instance, stainlesssteel, elgiloy, nickel, titanium, nitinol, shape memory polymers, orcombinations thereof. There are numerous materials that can be used forfloating element 50/50′/50″ to achieve the desired properties for theinterface of the engaging portion 52/52′/52″ with the engaging bumper42/42′/42″ of the delivery assembly 30. Some examples can includemetals, metal alloys, polymers, metal-polymer composites, and the like,or any other suitable material. Examples of suitable metals and metalalloys can include stainless steel, nickel-titanium alloy such as asuperelastic (i.e., pseudoelastic) or linear elastic nitinol;nickel-chromium alloy; nickel-chromium-iron alloy; cobalt alloy;tungsten or tungsten alloys; tantalum or tantalum alloys, gold or goldalloys, or the like; or other suitable metals, or combinations or alloysthereof. Examples of some suitable polymers can include, but are notlimited to, polyoxymethylene (POM), polybutylene terephthalate (PBT),polyether block ester, polyether block amide (PEBA), fluorinatedethylene propylene (FEP), polyethylene (PE), polypropylene (PP),polyvinylchloride (PVC), polyurethane, polytetrafluoroethylene (PTFE),polyether-ether ketone (PEEK), polyimide, polyamide, polyphenylenesulfide (PPS), polyphenylene oxide (PPO), polysufone, nylon,perfluoro(propyl vinyl ether) (PFA), polyether-ester, polymer/metalcomposites, or mixtures, blends or combinations thereof. Further, theengaging portion 52/52′/52″ of the floating device 50/50′/50″ may beformed by etching or cutting a pattern from a tube or sheet, or may beformed by one or more wires or ribbons of suitable materials woven,braided or otherwise formed into a desired shape and pattern. Further,the engaging bumpers 42/42′/42″ and/or the stopper bumpers 44/44′/44″may be radiopaque, in which case they function as markers to facilitatedetermination of delivery wire 31 position.

The engaging portion 52/52′/52″ of each floating element 50/50′/50″ mayhave one of a funnel-like, flower-like, and skirt-like configuration.Various embodiments of the floating element 50/50′/50″ are depicted inFIGS. 6-8. For example, with reference to FIG. 6, a floating element 50a comprises a funnel-like configuration, where the engaging portion 52includes a bent section 55 disposed between two straight sections 54 and56. The bent section 55 is configured to be elastically compressible,for instance, by heat-setting a stainless steel or shape memory alloy(e.g., nitinol). The engaging portion 52 extends from the annularportion 51 of the floating element 50 a, and is formed of suitablefilaments or ribbons woven, braided or formed into a mesh. It should beappreciated that the engaging portion 52 of the floating element 50 amay be formed of a solid material, such as a liner, cover, or the like.Alternatively, the liner or cover may be permeable, porous, or includesapertures or perforations (not shown).

With reference to FIG. 7, a floating element 50 b comprises aflower-like configuration, where the engaging portion 52 includes aplurality of petal-like elements 52 a-g extending from the annularportion 51. The petal-like elements 52 a-g may be formed by loopedfilaments 57 coupled to the annular portion 51, where each of the loopedfilament 57 may have a respective braided cover 59 disposed therein. Itshould be appreciated that the petal-like elements 52 a-g of theengaging portion 52 of the floating element 50 b may be formed by thelooped filaments 57 without any braided cover disposed therein, or thepetal-like elements 52 a-g may be formed of a solid material, such as aliner, cover, or the like. Alternatively, the liner or cover may bepermeable, porous, or includes apertures or perforations (not shown).The petal-like elements 52 a-g may overlap with respective adjacentlydisposed petal-like elements, as shown in FIG. 7.

With reference to FIGS. 8A-8B, the engaging portion 52 of a floatingelement 50 c comprises a plurality of flaps 60 having respective ends60′ coupled to or extending from the annular portion 51. It should beappreciated that the plurality of flaps 160 of the engaging portion 52of the floating element 50 c may be permeable, porous, or includesapertures or perforations (not shown).

Having described the function and structure of the implant deliverysystem 10, one method 100 of using the implant delivery system 10illustrated in FIG. 2 will now be discussed in FIG. 9. First, theimplant delivery system 10 is introduced into the vasculature of apatient in a conventional manner, such that the distal portion 16 of theelongate member 12 is adjacent a target site within the vasculature ofthe patient (step 102). Next, the delivery wire 31 is axially translatedin the distal direction relative to the elongated member 12, whilelimiting linear translation of the first (in this case the distal)floating element 50′ between the first (in this case, the distal)engaging bumper 42′ and the first (in this case, the distal) stopperbumper 44′ (step 104). Next, the distal engaging bumper 42′ is engagedwith the engaging portion 52′ of the distal floating element 50′, suchthat the distal floating element 50′ radially expands outward tofrictionally engage the implant 20 (step 106). Then, the delivery wire31 is further axially translated relative to the elongate member 12 inthe distal direction, thereby advancing the implant 20 within the lumen17 of the elongate member 12 (step 108). The delivery wire 31 is axiallytranslated relative to the elongate member 12 until the implant 20 atleast partially deploys out of the lumen 17 of the elongate member 12(step 110).

If the implant 20 is only partially deployed, the implant 20 may beresheathed back into the elongate member 20 if it is decided that thedeployment site of the implant 20 is not inaccurate. In particular, thedelivery wire 31 is axially translated relative to the elongate member12 in the proximal direction, while limiting linear translation of thesecond (in this case the proximal) floating element 50″ between thesecond (in this case, the proximal) engaging bumper 42″ and the second(in this case, the proximal) stopper bumper 44″ (step 112). The distalengaging bumper 42′ is disengaged from the engaging portion 52′ of thedistal floating element 50′, such that the distal floating element 50′radially contracts inwards to release the implant 20 (step 114). Next,the proximal engaging bumper 42″ is engaged with the engaging portion 52of the proximal floating element 50″, such that the proximal floatingelement 50″ radially expands outward to frictionally engage the implant20 (step 116). Optionally, the delivery wire 31 is further axiallytranslated relative to the elongate member 12 in the proximal direction,thereby resheathing the implant 20 within the lumen 17 of the elongatemember 12 (step 118). The distal portion 16 of the elongate member 12can be repositioned (step 120), and steps 102-110, and if necessarysteps 112-118, can be repeated.

Although particular embodiments of the disclosed inventions have beenshown and described herein, it will be understood by those skilled inthe art that they are not intended to limit the disclosed inventions,and it will be obvious to those skilled in the art that various changesand modifications may be made (e.g., the dimensions of various parts).The specification and drawings are, accordingly, to be regarded in anillustrative rather than restrictive sense.

1. An implant delivery system, comprising: an elongate tubular memberhaving a lumen; a tubular implant coaxially disposed within the lumen ofthe elongate tubular member; and a delivery assembly having a distalportion coaxially disposed within tubular implant, the delivery assemblycomprising: a delivery wire; an engaging bumper fixedly coupled to thedelivery wire; a stopper bumper fixedly coupled to the delivery wire;and a floating element slidably coupled around the delivery wire anddisposed between the bumpers, the floating element comprising anengaging portion configured to engage the engaging bumper when thedelivery wire is axially translated relative to the elongate tubularmember in a first direction, wherein the floating element is configuredto radially expand and frictionally engage the implant when the engagingportion of the floating element engages the engaging bumper.
 2. Theimplant delivery system of claim 1, the floating element furthercomprising an annular portion slidably disposed around the deliverywire, the annular portion configured to contact the stopper bumper whenthe delivery wire is axially translated relative to the elongate tubularmember in a second direction opposite to the first direction, andwherein the floating element is configured to maintain a non-radiallyexpanded configuration in which the floating element does notfrictionally engage the implant when the annular portion of the floatingelement contacts the stopper bumper.
 3. The implant delivery system ofclaim 2, wherein the annular portion of the floating element has anabutting surface, and the stopper bumper has an abutting surface thatabuts the abutting surface of the floating element when the deliverywire is axially translated relative to the elongate member in the seconddirection.
 4. The implant delivery system of claim 3, wherein theabutting surface of the stopper bumper is perpendicular to the seconddirection.
 5. The implant delivery system of claim 1, wherein thefloating element radially expands by flaring outward when the engagingportion of the floating element engages the engaging bumper.
 6. Theimplant delivery system of claim 1, wherein the engaging portion of thefloating element has an inner surface, and the engaging bumper has anouter surface that contacts the inner surface of the floating elementwhen the delivery wire is axially translated relative to the elongatemember in the first direction.
 7. The implant delivery system of claim6, wherein the outer surface of the engaging bumper tapers inwardstowards the engaging portion of the floating element.
 8. The implantdelivery system of any of claim 1, wherein the engaging portion of thefloating element has one of a funnel-like, flower-like, and skirt-likeconfiguration.
 9. The implant delivery system of claim 8, wherein theengaging portion of the floating element has a funnel-like configurationincluding an elastically compressible bent section disposed between twostraight sections.
 10. The implant delivery system of claim 8, whereinthe engaging portion of the floating element has a flower-likeconfiguration including a plurality of petal-like elements.
 11. Theimplant delivery system of claim 8, wherein the engaging portion of thefloating element has a flower-like configuration including a pluralityof flaps.
 12. An implant delivery system, comprising: an elongatetubular member having a lumen; a tubular implant coaxially disposedwithin the lumen of the elongate tubular member; and a delivery assemblyhaving a distal portion coaxially disposed within tubular implant, thedelivery assembly comprising: a delivery wire; a first set of bumpersincluding a first engaging bumper and a first stopper bumper fixedlycoupled to the delivery wire; a second set of bumpers including a secondengaging bumper and a second stopper bumper fixedly coupled to thedelivery wire; and a set of floating elements including a first floatingelement and a second floating element slidably coupled around thedelivery wire; wherein the first floating element is disposed betweenthe first engaging bumper and the first stopper bumper thereby limitinglinear translation of the first floating element therebetween, the firstfloating element comprising an engaging portion configured to engage thefirst engaging bumper when the delivery wire is axially translatedrelative to the elongate member in a first direction, wherein the firstfloating element is configured to radially expand and frictionallyengage the implant when the engaging portion of the first floatingelement engages the first engaging bumper; and wherein the secondfloating element is disposed between the second engaging bumper and thesecond stopper bumper, thereby limiting linear translation of the secondfloating element therebetween, the second floating element comprising anengaging portion configured to engage the second engaging bumper whenthe delivery wire is axially translated relative to the elongate memberin a second direction opposite the first direction, wherein the secondfloating element is configured to radially expand and frictionallyengage the implant when the engaging portion of the second floatingelement engages the second engaging bumper.
 13. The implant deliverysystem of claim 12, the first floating element further comprising anannular portion slidably disposed around the delivery wired, the annularportion configured to contact the first stopper bumper when the deliverywire is axially translated relative to the elongate member in the seconddirection, wherein the first floating element is configured to maintaina non-radially expanded configuration in which the first floatingelement does not frictionally engage the implant when the annularportion of the first floating element contacts the first stopper bumper,and the second floating element further comprising an annular portionslidably disposed around the delivery wired, the annular portionconfigured to contact the second stopper bumper when the delivery wireis axially translated relative to the elongate member in the firstdirection, wherein the second floating element is configured to maintaina non-radially expanded configuration in which the second floatingelement does not frictionally engage the implant when the annularportion of the second floating element contacts the second stopperbumper.
 14. The implant delivery system of claim 13, wherein the annularportion of the first floating element has an abutting surface, and thefirst stopper bumper has an abutting surface perpendicular to the seconddirection that abuts the abutting surface of the first floating elementwhen the delivery wire is axially translated relative to the elongatemember in the second direction; and wherein the annular portion of thesecond floating element has an abutting surface, and the second stopperbumper has an abutting surface perpendicular to the first direction thatabuts the abutting surface of the second floating element when thedelivery wire is axially translated relative to the elongate member inthe first direction.
 15. The implant delivery system of claim 12,wherein each of the first floating element and second floating elementradially expands by flaring outward.
 16. The implant delivery system ofclaim 12, wherein the engaging portion of the first floating element hasan inner surface, and the first engaging bumper has an outer surfacethat tapers towards the engaging portion of the first floating elementand engages the inner surface of the first floating element when thedelivery wire is axially translated relative to the elongate member inthe first direction; and wherein the engaging portion of the secondfloating element has an inner surface and the second engaging bumper hasan outer surface that tapers towards the engaging portion of the secondfloating element and that engages the inner surface of the secondfloating element when the delivery wire is axially translated relativeto the elongate member in the second direction.
 17. The implant deliverysystem of claim 12, wherein the respective engaging portions of thefirst and second floating elements have one of a funnel-like,flower-like, and skirt-like configuration.
 18. A method of operating theimplant delivery system of claim 1, the method comprising: axiallytranslating the delivery wire relative to the elongate member in a firstdirection, while limiting linear translation of the first floatingelement between the first engaging bumper and the first stopper bumper;engaging the first engaging bumper with an engaging portion of the firstfloating element, such that the first floating element radially expandsoutward to frictionally engage the implant; and further axiallytranslating the delivery wire relative to the elongate member in thefirst direction, thereby advancing the implant within the lumen of theelongate tubular member.
 19. The method of claim 18, wherein thedelivery wire is further axially translated relative to the elongatemember until the implant at least partially deploys out of the lumen ofthe elongate tubular member.
 20. (canceled)